      subroutine graeff(a,b)
      real*8 a(11),b(11)
c
c     --  Graeffe Root-Squaring Method   --
c     --  to Find Roots of a Polynomial  --
c
      b(1)=a(11)**2
      b(2)=-a(10)**2+2.0*a(9)*a(11)
      b(3)=a(9)**2-2.0*a(8)*a(10)+2.0*a(7)*a(11)
      b(4)=-a(8)**2+2.0*a(7)*a(9)-2.0*a(6)*a(10)+2.0*a(5)*a(11)
      b(5)=a(7)**2-2.0*a(6)*a(8)+2.0*a(5)*a(9)-2.0*a(4)*a(10)+2.0*a(3)*a
     . (11)
      b(6)=-a(6)**2+2.0*a(5)*a(7)-2.0*a(4)*a(8)+2.0*a(3)*a(9)-2.0*a(2)*a
     . (10)+2.0*a(1)*a(11)
      b(7)=a(5)**2-2.0*a(4)*a(6)+2.0*a(3)*a(7)-2.0*a(2)*a(8)+2.0*a(1)*a(
     . 9)
      b(8)=-a(4)**2+2.0*a(3)*a(5)-2.0*a(2)*a(6)+2.0*a(1)*a(7)
      b(9)=a(3)**2-2.0*a(2)*a(4)+2.0*a(1)*a(5)
      b(10)=-a(2)**2+2.0*a(1)*a(3)
      b(11)=a(1)**2
      return
      end
